Lubricant compositions comprising chlorinated quinones



United States Patent Delaware N0 Drawing. Filed June 28, 1961, Ser. No. 120,166 18 Claims. ((31. 2 52-334) This invention relates to improved mineral lubricating oil compositions, suitable for the lubrication of heavy duty diesel engines containing lubricated silver parts, comprising an overbased metal sulfonate and a chlorinated quinone.

Diesel oils for heavy duty service have been prepared heretofore employing the so-called overbased detergents, comprising detergent metal salts of various types such as alkylphenolates, sulfonates, salts of phosphorus sulfides olefin reaction products, etc., together with solubilized basic metal compounds, as a means of obtaining both high detergency and anti-corrosiveness to copper-lead bearings. A particularly successful commercial diesel lubricant for heavy duty service contains .an overbased detergent in an amount suflicient to give a high alkaline reserve represented by a total base number of about 2.5. However, a need has developed for a diesel lubricant having still higher detergency and anti-c-orrosiveness in combination with improved silver lubricating properties also, due to the increasing severity of diesel engine operating conditions, including the increasing use of low cost, high sulfur fuels, containing above 0.4 percent of sulfur, and to the increased use of diesel engines containing lubricated silver parts. The desired combination of high detergency and good silver lubricating properties is not obtained in lubricating compositions of the prior art, since compositions containing very eifective detergents are generally characterized by poor silver lubricating properties, and the overbased detergents in particular badly degrade the silver lubricating properties of mineral lubricating oil compositions.

It has now been found, in accordance with this invention, that the combination of extremely high detergency and anti-corrosiveness to copper-lead bearings together with good silver lubricating properties is obtained in mineral oil compositions by employing an additive combination comprising a highly overbased metal sulfonate in a sufficient amount to give a total base number above about 3 in the composition and a small amount of a chlorinated quinone. Lubricating compositions are .thus obtained which are suitable for use in large high'speed diesel engines under adverse operating conditions, including the use of the low grade high sulfur fuels, and also for meeting the proposed revision of Navy Specification MILL- 9000B (Ships), callingfor good silver lubricating properties in addition to the requirement of approximately Supplement I level detergency.

By total base number is meant the titratable a1kalinity of the composition as milligrams of potassium hydroxide per gram of the composition. The titration is carried out electrometrically to a pH of 4, employing a standard hydrochloric acid solution.

The efiect of the chlorinated quinones in imparting good silver lubricating properties to these compositions was entirely unpredictable and unexpected, since the high silver wear obtained with highly detergent compositions containing overbased metal sulfonates is apparently due primarily to the difiiculty in wetting and maintaining good lubricating films upon silver surfaces with compositions of this type, and no correlation has been found between either chemical type or lubricating properties otherwise.

Compounds which have been 3,19%,834 Patented June 22, 1965 i ce tested unsuccessfully for this purpose have included other chlorine-containing organic compounds of various types having extreme pressure properties and also load bearing additives of various types.

The overbased metal sulfonates are basic reacting materials containing metal in excess of that required to neutralize the sulfonic acids, the manner in which the excess metal base is maintained in solution being not entirely understood. They are conveniently prepared by heating together a suitable sulfonic acid with a metal base such as metal oxide or carbonate in an amount in excess of that required to form the metal sulfonate, in the presence of a promoter of some sort as described, for example, in US. 2,616,911, US. 2,616,926, US. 2,856,360 and US. 2,856,361. Compositions comprising overbased metal sulfonaites in admixture with metal soaps and other compounds which are also suitable for use in accordance with this invention may be prepared by various methods such as by carrying out an oxidation step upon a mixture of metal sulfonate and excess metal base in a mineral lubricating oil, as described for example by H. D. Kluge, K. L. Kruz and M. A. Wiley in their copending application, Serial No. 791,820, filed February 9, 1959. Sulfonic acids which may be employed to form the overbased sulf-onates include alkyl sulfonic acids, alkaiyl sulfonic acids, cycloaliphatic sulfonic acids, the .so-called mahogany sulfonic acids and the like, containing sufficient aliphatic carbon atoms to impart oil solubility to the metal salts, sulfonic acids having molecular weights in about the range 350- 500 being particularly suitable for this purpose.

The highly overbased metal sulfonates which are employed in accordance With this invention are those wherein the metal is an alkali metal or an alkaline earth metal, containing excess metal in an amount equivalent to at least about a 200 percent excess over that required to form the normal sulfonic acid salts, and having a total base number of at least 100. Particularly suitable materials of this character are those containing excess metal equal to about a 300-600 percent excess over that required to form the normal sulfonate and having a total base number in about the range 200-700, the preferred materials containing about 425-475 percent of excess metal and having a total base number of about 280-610. The overbased metal .sulfonates are employed in the composition in an amount from about 0.1 to about 10 7 percent by Weight, and ordinarily in an amount from about as a total basenumber in the range from about 5 to about 15.

The chlorinated quinones employed in the compositions of this invention are substituted benzoquinones represented by the formula:

II C G RII g RIII ll 0 wherein R, R, R and R represent hydrogen, chlorine or aliphatic hydrocarbon groups, including unsaturated groups, particularly C unsaturated groups, forming a fused ring with the benzoquinone group and represented by R and R together, at least one of the substituents represented by R, R, R or R being chlorine. Other aliphatic groups which may be represented by R, R, R

and R are chiefly lower alkyl groups containing from 1 to about 6 carbon atoms, although compounds containing higher aliphatic substituent groups, containing up to about 30 carbon atoms per molecule, have the advantage of imparting oil solubility to the compound and are also contemplated. Examples of suitable chlorinated quinones include tetrachloro-parabenzoquinone (chloranil), 1,2-dichloro-3,4-dimethyl-parabenzoquinone, 1,3-dichloro-2,4- dibutyl-parabenzoquinone, l,2,3-trichloro-4-dodecyl-parabenzoquinone and 2,3-dich1oro-l,4-naphthoquinone (dichlone). A compound or compounds of this class may be employed in the lubricant composition in an amount in about the range 0.01-2 percent by weight of the composition. They are preferably employed in an amount from about 0.05 to about 1 percent by weight, based on the weight of the composition.

The lubricant compositions contemplated herein may also very advantageously contain, in addition to the overbased metal sulfonate and chlorinated quinone, a dicyclic terpene-phosphorus sulfide reaction product, as an antioxidant and corrosion inhibitor for the protection of copper-lead bearings. Materials of this character are obtained by reacting dicyclic terpenes such as pinene, camphene and fenchene with a phosphorus sulfide such as P P 8 P 8 P 5 P 8 etc., at a temperature above about 100 C., employing about 1 mol of phosphorus sulfide for every 4 mols of dicyclic terpene. The preferred material of this character is a reaction product obtained by reacting pinene with P 5 This additive may be suitably employed in the composition in an amount from about 0.05 to about 5 percent and preferably from about 0.2 to about 2 percent by weight of the composition.

Another class of additives which may be very advantagcously employed in these compositions are oil soluble sulfurized monocyclic terpenes, obtained by heating a monocyclic terpene such as dipentene, tcrpinolene, lirnoncue, sylvestrene, etc., with elemental sulfur under pressure, so as to obtain a product containing about -50 percent by weight of sulfur, and preferably about -40 percent by weight of sulfur. A material of this character may suitably be employed in an amount from about 0.05 to about 5 percent and preferably from about 0.1 to about 1.0 percent by weight of the composition.

Still another class of additives which may be very advantageously employed in these compositions are alkaline earth metal phenolates containing at least one aliphatic substituent group containing from about 3 to about 31 carbon atoms in the molecule and also including the sulfides of such compounds. Such compounds may be suitably employed in the composition in amounts from about 0.05 to about 5 percent by weight.

Various other additives such as are commonly employed in crankcase oils as antioxidants, corrosion inhibitors, detergents, etc., may also be employed in these compositions where there is no incompatibility or adverse effect upon the desired properties as described herein.

The lubricating oils employed in these compositions may be any mineral lubricating oils of suitable viscosity obtained by any of the conventional refining processes from parafiinic, naphthenic or mixed base crudes. They are preferably refined distillate oils comprising at least a major portion of a paraiiinic distiilate oil, having a Saybolt Universal viscosity at 210 F. in about the range 50-150 seconds.

The following examples describe representative compositions embodying this invention.

EXAMPLE I A lubricant having the following composition in percent by weight:

Overbased calcium sulfonate solution 2.0 Chloranil 0.1 Mineral lubricating oil Remainder The overbased calcium sulfonate employed in the above composition is a carbon dioxide-neutralized product con- Kinematic viscosity:

at F. 3M5 at 210 F. 26.4 Total base number 299 C0 percent 10.0 Ca, percent 11.3

The lubricant composition is prepared by mixing together the above materials in the indicated proportions by weight and heating at about F. until a clear solution is obtained.

The above composition has both excellent detergency and a high alkaline reserve indicated by a total base number of about 6. In addition, it has excellent silver lubricating properties as shown by the results obtained in the so-called Immersion Type Friction and Wear Machine Test.

The Immersion Type Friction and Wear Machine Test is a bench test for determining the silver lubricating properties of a lubricant in terms of the coefficient of friction and of wear upon a lubricated silver surface. The apparatus employed comprises essentially a flat steel rotating disk and a 0.09 inch diameter cylindrically ended silver pin, which is loaded against the rotating steel disk by means of dead weights acting through a shaft supported by needle hearings in such a manner that it can slide along and rotate about its axis. A strain ring and a Baldwin- Sanborn strain gauge recorder which are connected to the shaft indicate the tendency of the shaft to rotate due to the frictional force between the rotating steel disk and the silver pin. A dial gauge at the top of the shaft indicates the amount of upward movement of the shaft due to wear of the silver pin. In carrying out the test, the pin and disk assembly are immersed in the test oil maintained at 285 :5 F., and the silver pin under an eight kilogram load is slid against the steel disk at 76.3 centistokes per second by rotating the disk at 376 rpm. for periods from 2 to 4 hours. The Wear of the silver pin is determined by measuring the length of the pin before and after the operation. The wear coefficient is volume of wearX hardness load sliding distance 12.2 cm.)

' Immersion type friction and wear machine test Friction Wear C0- Composrtion Ooerfiefllcient clent X 10 Mineral lubricating oil+2.0% overbased Ca suitonate O. 05 4. 6 Mineral lubricating 0il+2.0% overbased Ca sulfonatc+0.05% chloranil. 0.015 0.35 Mineral lubricating oil+2.0% overbased Ca sulf0- nate+0.1% chlorauil- 0. 004 0.10

EXAMPLE II A lubricant having the following composition in percent by weight:

The overbased barium sulfonate containing additive is a material obtained as disclosed in the above-mentioned copending application Serial No. 791,820, by the method comprising air blowing'a mixturecomprising a paraffinic lubricating oil, about 11 percent by weight based on the weight of the lubricating oil of basic barium sulfonate and about 17 percent by weight based on the weight of the lubricating oil of barium oxide at 350450 F. for hours at an air rate of about 132 standard cubic feet per minute of air per 4755 pounds of reaction mixture. The product has a barium content of 8.9 percent, representing about a 300 percent. excess of barium over that required to form the normal barium'salts.

The sulfurized terpene is a commercial product having a kinematic viscosity at 210 F. of 39.9 and a sulfur content of 35.5 percent.

The above composition has excellent detergency and anti-corrosive properties and in addition it has very good silver lubricating properties as shown by the results obtained in the Silver Disk Torque Test.

The Silver Disk Torque Test measures the frictional drag of a rotating steel ball on silver disks, replacing the three standard steel balls in a standard Four Ball Wear Tester. A specimen holder in the apparatus holds the silver disks so that they contact the rotating ball at the same points as the standard balls ordinarily employed. The disk holder is restricted from turning about its axis of rotation by the free end of a horizontally mounted cantilever beam, which bends to the amount of frictional torque developed. SR-4 strain patches mounted near the fixed end of the beam electronically translate the amount of bending into electrical signals which are read on a Baldwin SR-4 circular charge reactor, resulting in a continuous plot of torque versus running time. In carrying out the test, the steel ball is rotated at a speed of 1800 r.p.m., resulting in a rubbing speed of 136 feet per minute under the load of 50 kilograms for 3 minutes, while the ball and disk assembly is immersed in the test oil maintained at 350 F. A rating below 500 is considered indicative of good silver lubricating properties.

The data given below which were obtained in the above test show the eifect of the chlorinated quinoue upon the silver lubricating properties of the composition containing highly overbased barium sulfonate.

Silver disk torque test Composition: Rating Mineral oil+4.6% overbased Ba sulfonate +02% sulfurized terpene 600 Mineral oil+4.6% overbased Ba sulfonate +02% sulfurized terpene+0.2% dichlone 285 The overbased calcium sulfonate is that described in Example I. l

. The phospho-sulfurized terpene is a commercial product obtained by reacting alpha-pinene with P 8 Typi- 6 cal inspection tests on this material include a kinematic viscosity of 652.2 at F. and 19.03 at 212 F., a neutralization number ST-47A of 3.5, a sulfur content of 13.9 percent and a phosphorus content of 5.36 percent by weight.

The mineral lubricating oil is a 70 VI blend comprising 68 percent by volume of refined distillate oil having a Saybolt Universal viscosity at 210 F. of about 93, 5 percent by volume of a naphthenic distillate oil having a Saybolt Universal viscosity at 210 F. of 92, and 27 percent by volume of a'refined naphthenic distillate 'oil having a Saybolt Universal viscosity at 210 F. of about 54.

The above composition has given excellent performance, including exceptional engine cleanliness, low corrosiveness and good silver lubrication in a high speed, high load, engine test carried out in a GM-567A Electromotive Diesel 6 cylinder engine utilizing a high sulfur (1 percent) content economy diesel fuel, under the following conditions:

A total demerit rating, indicative of engine cleanliness, of only 146 was obtained in this test with the lubricant composition of Example 111, as compared with 254 for a commerical diesel lubricant containing an overbased detergent comprising calcium sulfonate and barium alkylphenolate sulfide, and having a total base number of 2.4. In addition, the silver bushings and trunnions were in excellent condition at the end of this test, whereas the same composition Without the chlorinated quinoue gave very poor silver lubrication, resulting in wiped silver bushings and severely damaged silver trunnions after only 24 hours in the above test.

EXAMPLE IV A lubricant having the following composition in percent by weight:

Overbased magnesium sulfonate solution 2.5 Phospho-sulfurized terpene 1.3 4,4-methylene bis(2,6-ditertiary butyl phenol) 0.1 Phenylalphanaphthylamine 0.15 Chloranil 0.1 Mineral lubricating oil Remainder The overbased magnesium sulfonate is a partially carbon dioxide-neutralized product containing excess magnesium equivalent to about a 450 percent excess over that required to form the normal mangesium sulfonate. It is employed in the form of a 50 percent solution in a refined mineral lubricating oil, typical inspection tests upon this solution including the following:

The phospho-sulfurizedterpene and the mineral lubricarting oil are the same as those described in Example III. The composition has a total base number of 7.5. It has given very satisfactory performance in the EMD engine test described above, whereas the same composition without the chlorinated quinoue employed 'in this test results in badly damaged silver bushings and trunnions after 24 hours.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

Iclaim:

1. A lubricating composition comprising essentially a mineral lubricating oil containing about 01-10 percent by weight, sufficient to give a total base number above about 3 to the composition, of an overbased metal sulfonate having a total base number of at least 100 and containing metal equal to at least a 200 percent excess over that required to form the normal metal sulfonate, said metal being chosen from the class consisting of alkali metals and alkaline earth metals, and about 0.01- 1 0.2 percent by Weight of a chlorinated quinone represented by the formula wherein R, R, R and R" represent members of the class consisting of hydrogen, chlorine and aliphatic hydrocarbon groups containing from 1 to about carbon 30 atoms, at least one of which represents chlorine, and wherein R and R taken together may represent an un saturated hydrocarbon group forming a fused ring with the quinone group of the formula, said composition without the said chlorinated quinone being deficient in silver lubricating properties and said chlorinated quinone imparting substantially improved silver lubricating properties to the said composition.

-2. The composition of claim 1 wherein the said chlorinated quinone is tctrachloro-parabenzoquinone. 49

3. The composition of claim 1 wherein the said chlorinated quinone is 2,3-dichloro-1,4-naphthoquinone.

4. The composition of claim 1 containing about 0.2-2 percent by weight of phospho-sulfurized terpene obtained by reacting a terpene with a phosphorus sulfide. ,5

5. The composition of claim 1 containing about 0.2-2 percent of a sulfurized monocyclic terpene.

6. The composition of claim 1 wherein the said metal is calcium.

7. The composition of claim 1 wherein the said metal is 50 barium.

8. The composition of claim 1 wherein the said metal is magnesium.

9. The composition of claim 1 wherein the said metal sulfonate has a total base number of about 200-700 and contains excess metal equivalent to at least 300 percent over that required to form the normal metal sulfonate.

10. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, sufiicient to give a total base number of at least 5 to the composition, of an overbased calcium sult'onate having a total base number of about 200-700 and containing excess calcium equivalent to at least about a 300 percent excess over that required to form the normal calcium sulfonate, about 0.2-2.0 percent by Weight of an 5 alpha pinene-P S reaction product and about 0.05-0.2 percent by weight of tetrachloro-parabenzoquinone.

11. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, sufiicient to give a total base number of at least 5 to the composition, of an overbased calcium sulfonate having a total base number of about 200-700 and containing excess calcium equivalent to at least about a 300 percent excess over that required to form the normal calcium sulfonate, about 0.2-2.0 percent by weight of an alpha pinene-P S reaction product and about 0.050.2 percent by weight of 2,3-dichloro-1,4-naphthoquinone.

12. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, sufiicient to give a total base number of at least 5 to the composition, of an overbased barium sulfonate having a total base number of about 200-700 and containing excess barium equivalent to at least about a 300 percent excess over that required to form the normal barium sulfonate, about 0.2-2.0 percent by weight of an alpha pinene-P S reaction product and about 0.05-0.2 percent by Weight of tetrachloro-parabenzoquinone.

13. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, suflicient to give a total base number of at least 5 to the composition, of an overbased barium sulfonate having a total base number of about 200-700 and containing excess barium equivalent to at least about a 300 percent excess over that required to form the normal barium sulfonate, about 0.2-2.0 percent by Weight of an alpha pinene-P S reaction product and about 0.05-0.2 percent by weight of 2,3-dichloro-1,4-naphthoquinone.

14. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, sufficient to give a total base number of at least 5 to the composition, of an overbased magnesium sulfonate having a total base number of about 200-700 and containing excess magnesium equivalent to at least about a 300 percent excess over that required to form the normal magnesium sulfonate, about 0.2-2.0 percent by weight of an alpha pinene-P S reaction product and about 0.05- 0.2 percent by weight of tetrachloro-parabenzoquinone.

15. A lubricating composition comprising essentially a mineral lubricating oil containing about 0.5-5 percent by weight, sufficient to give a total base number of at least 5 to the composition, of an overbased magnesium sulfonate having a total base number of about 200-700 and containing excess magnesium equivalent to at least about a 300 percent excess over that required to form the normal magnesium sulfonate, about 0.2-2.0 percent by weight of an alpha pinene-P S reaction product and about 0.050.2 percent by weight of 2,3-dichloro-1,4-naphthoquinone.

16. A method of lubricating an internal combustion engine having lubricated silver parts which comprises supplying to the lubricated parts thereof a lubricating composition comprising essentially a mineral lubricating oil containing about 0.1-10 percent by weight, sufi'icient to give a total base number above about 3 to the composition, of an overbased metal sultonate having a total base member of at least and containing metal equal to at least a 200 percent excess over that required to form the normal metal sulfonate, said metal being chosen from the class consisting of alkali metals and alkaline earth metals, and about 0.01-2 percent by weight of a chlorinated quinone represented by the formula wherein R, R, R" and R' represent members of the class consisting of hydrogen, chlorine and aliphatic hydrocarbon groups containing from 1 to about 30 carbon atoms, at least one of which represents chlorine, and wherein R and R taken together may represent an unsaturated hydrocarbon group forming a fused ring with the quinone group of the formula, said composition without the said chlorinated quinone being deficient in silver lubricating properties and said chlorinated quinone imparting substantially improved silver lubricating properties to the said composition.

17. The method of claim 16 wherein the said ch10rinated quinone is tetrachloro-parabenzoquin0ne.

18. The method of claim 16 wherein the said chlorinated quinone is 2,3-dich1oro-1,4-naphthoquinone.

References Cited by the Examiner UNITED STATES PATENTS 10 Evans 25254 XR Adelson 25254 Sands 25233.4 Heisig et a1. 25233.4

DANIEL E. WYMAN, Primary Examiner.

JOSEPH R. LIBERMAN, ALPHONSO D. SULLIVAN,

Examiners. 

1. A LUBRICATING COMPOSITION COMPRISING ESSENTIALLY A MINERAL LUBRICATING OIL CONTAINING ABOUT 0.1-10 PERCENT BY WEIGHT, SUFFICIENT TO GIVE A TOTOAL BASE NUMBER ABOVE ABOUT 3 TO THE COMPOSITION, OF AN OVERBASED METAL SULFONATE HAVING A TOTAL BASE NUMBER OF AT LEAST 100 AND CONTAINING METAL EQUAL TO AT LEAST A 200 PERCENT EXCESS OVER THAT REQUIRED TO FORM THE NORMAL METAL SULFONATE, SAID METAL BEING CHOSES FROM THE CLASS CONSISTING OF ALKALI METALS AND ALKALINE EARTH METALS, AND ABOUT 0.010.2 PERCENT BY WEIGHT OF A CHLORINATED QUINONE REPRESENTED BY THE FORMULA 